Variable condenser



April 13 192s. 1,580,173

J. L. SECOR VARIABLE. CONDENSER Filed Feb. 2. 1924 73 Mllllll llllllHl WEI lllllmm:

Patented Apr. 13, 1926.

UNHTE rarest VARIABLE CONDENSER.

Application filed February 2, 1924. Serial No. 690,195.

T 0 all whom it may concern:

Be it known that 1, JAMES LINDON Snoon,

a citizen of the United States, residing at Mountainville, in the county of Orange and State of New York, have invented certain new and useful Improvements in Variable Condensers, of which the following is a specification. I

This invention relates to variable condensers such as are used in connection with radio apparatus and it provides for certain novel and advantageous improvements in the condenser whereby it is susceptible of very fine regulation at the will of the operator in adjusting the capacity of t is condenser.

Specifically, the invention provides a device that can be used on a variable condenser of any number of plates, either as an attach inent therefor or as a built-in part of the condenser structure; the said device being operable either for bringing into use or cutting out any desired number of the condenser plates which are so insulated and arranged as to make each plate a separate unit.

lVith the above and other objects in View, the invention resides in the construction, arrangement, and combination of parts hereinafter more fully pointed out and described with reference to the accompanying drawing, wherein:

Figure 1 is a side view of a conventional condenser having the invention applied thereto.

Figure 2 is an end elevation of the same.

Figure 3 is a top plan view of the condenser.

Figure 4 is a vertical longitudinal sectional view.

Figure 5 is a detail view of the notched conducting plate, and V Figure 6 1s a detail view of one of the contact fingers.

Describing the invention in detail, the parts 10 and 11 are the supporting panels of a conventional variable condenser, the plates 12 of which are shown mounted in their usually spaced apart relation between. the said panels, being supported on rods 13. lhese plates are, therefore, fixed and stationary with respect to plates 14 which are mounted to rotate on rod or shaft 15 so as to pass be tween plates 12 in the customary manner. Rod or shaft 15 is manually rotated by means of knob 16. 'With this structure is combined the essentia features of the invention which 1a., in mounting a switch at end of the condcnser; 2nd, ininsulating the condenser plates from each other, making each plate a separate unit and: 3rd, connecteach plate with contact means adapted to engage the switch} The said switch may, as illustrated, consist of a rotatable rod or cylinder 17 adapted to be manually turned by means of a knob 18 and having the opposite end extended beyond the panel 11 to be engaged by a spring contact 19, the latter being anchored to the binding post- 20 of the central supporting rod of the condenser plates 12. Cylinder '17 is of non-conducting material and partly covered by a metal conducting plate 21, which plate is provided with a plurality of notches, as shown in-Figure 6, to correspond with the number of contact lingers associated with the condenser plates 12.

Fiber washers 22, encircling the supporting rods 13 between the plates 12, serve to space theplates, one from the other, and also to insulate them in such manner that each plate is made a separate unit, the plates 12 being also insulated from the supporting rods 13. Electrical connection between the insulated plates 12 and the conducting plate 21 is established through the medium of contact fingers 23, one of which is shown in detail in Figure 5. These fingers are mounted on the support rod 13 below the switch 17 by means of brackets 24 integral therewith, and provided with an opening to accommodate the support rod, as may be understood from Figure 2.

Mounted on rod or shaft 15 which supports plates 14: is a metal contact strip 25 to which is soldered, or otherwise affixed, a conductor wire 26 which has its opposite end secured to binding post 27, the latter being carried bypanelll of the condenser. The various binding posts of the device permit the proper connecting up of the condenser with the radio apparatus. In using the device, the switch 17 is rotated until the number of fingers 23 desired are resting up on the conducting plate 21, thus charging the corresponding number of condenser plates while the remaining fingers will be resting upon the non-conducting portion of the cylinder, making their corresponding plates non-effective.

It will thus be seen that by means of the insulated plates and the provision of adjustable switch, as set forth above, the of the be convenient" ly and very finely adjusted since any number of the condenser plates can be brought into use, or cut out, as desired. The regulation is entirely at the will of the operator.

Experimental tests prove it to be very efficient in cutting out interference by reducing or increasing the number of plates in use, and also for bringing in many stations that otherwise could not be tuned in. s It is especially applicable to long distance stations for which it may be regulated with a fineness not otherwise obtainable. It presents, furthermore, advantages of economy in that it can be attached to the standard types of variable condensers now in use, or a variable condenser can be made with this attachment at very little extra expense.

Having thus described the invention, what is claimed as new, is

A variable condenser comprising pair of supporting panels, aplurality of metal spac ing rods connecting the said panels, one of said rods being rotatable and the other rods being fixed and stationary with respect to the rotatable rod, a plurality of cendenser plates immovably fixed on the said -2 sesame stationary rods and insulated therefrom, fiber washers encircling the said fixed rods and insulating the said removable plates frem each other, a plurality of smaller con denser plates fixed on the said rotatable rod to move therewith and being in relatively spaced relation so as to pass between the said immovable plates during the rotation of the said rotatable rod, said movable plates being in electrical connection with each other and withthe said rotatable rod, a binding post on one of the said panels, an electrical connection between the said binding post and,

the said rotatable rod, a second binding post provided at one end of one oft the said stationary rods, a plurality of metal brackets encircling another one of the said stationary rods and arranged thereon so that each bracket is in electrical contact with one of the said immovable plates, a contact finger extending from each bracket, and means for establishing electrical connection between the said binding post of the said stationary rod and all of the said fingers either simultaneously or in progression.

JAMES LINDON SECOR. 

